Organohalogenated Contaminants (OHCs) in Surface Sediments and Water of East Dongting Lake and Hong Lake, China

East Dongting Lake and Hong Lake are two typical lakes in the middle watershed of the Yangtze River, China. The differences in the hydrological condition and human activities of the region may result in the differences in concentrations, distribution, and sources of contaminants. The levels, sources, distribution, and ecological risk of OHCs, including 15 OCPs, 7 PCBs, and 7 PBDEs in surface sediments and water from this region, were investigated. OCPs and PCBs were the predominant pollutants in water and sediments samples, respectively. Source analysis showed that HCHs, PBDEs, and PCBs were mainly from the historical input of commercial products, but there were recent discharges of DDT into the water. The spatial distribution of OHCs showed that higher levels of OHCs in sediments and water were found in the sampling sites far away from the estuary of Hong Lake, but such obvious distribution characteristic was not found in East Dongting Lake. TOC played a crucial role in the retention of OCPs in the sediments of Hong Lake, but significant correlation between TOC and OCPs for East Dongting Lake, TOC and PCBs or PBDEs for both lakes were not found. The possible adverse biological effects could be caused by OCPs residues in sediments of both lakes, and it was worse for Hong Lake. The noncarcinogenic and carcinogenic risk assessment of HCHs and DDTs indicated the water quality of both lakes was safe for bathing and drinking. The potential ecotoxicological risks of PBDEs and PCBs of both lakes were rather low

Concentrations, Distribution, Sources and Ecological Risk Assessment of Trace Elements in Soils from Wuhan, Central China

This study aimed to determine the concentration levels, potential sources and ecological risks of eleven trace elements, namely Cr, Fe, Co, Ni, Cu, As, Sb, Cd, Zn, Hg and Pb, in the soil from Huangpi district, Wuhan, Central China. Soil samples were collected from eighteen sites at soil depths of 1-10 and 10-20 cm and analyzed using Inductively Coupled Plasma-Mass Spectrometer ICP-MS (Thermo X SERIES 2, Scientific and Innovative Technology Co. Ltd., Beijing, China). The recorded mean concentration of the elements were in a decreasing order of Fe > Co > Cr > Ni > Pb > Cu > As > Cd > Sb > Zn > Hg. The mean concentration of trace elements, soil pH and total organic carbon (TOC) were higher at a soil depth of 1-10 cm. The obtained mean concentration of Cr, Co, As, Cd, Ni, Cu, Hg and Pb were above the soil background values of Wuhan and Hubei Province. The mean concentration values of Co, Ni and Cd, exceeded the recommended FAO (Food and Agriculture Organization)/ISRIC (International Soil Reference and Information Centre) (2004) and WHO/FAO (2001) values. Pearson's correlation analysis illustrated that there was a strong and significant correlation between trace elements, whereas, a weak positive and negative correlation between elements and soil properties (pH and TOC). The principal component analysis (PCA) and cluster analysis (CA) result indicated that the concentration of trace elements in Huangpi soil were originated from anthropogenic sources. Potential ecological risk index (RI) of this study revealed that there is a high ecological risk of trace elements in the soil. Enrichment factor (EF) and geo-accumulation index (I-geo) of trace elements for this study indicated that the study area is strongly contaminated with Cd and Co. Generally, the finding of this research showed that Huangpi soil is contaminated